Synthesis, spectroscopic analysis, and computational-based investigations on 'azo-coumarin-Co(II)-galangin' hybrids exhibit multipotential activities.

The present study synthesized a series of cobalt (II) metal ion frame hybrid candidates (6a-6f) bearing phyto-flavonol galangin with substituted aryl diazenyl coumarins, and further structural confirmation was validated by various spectral techniques, including NMR, ATR-FTIR, UV-vis, HPLC, XRD, etc. Therapeutic potency was investigated via PASS (prediction of activity spectra for substances), molecular docking, molecular dynamics simulation, prediction of toxicity, pharmacokinetics, and drug-likeness scores, along with the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), with their energy gaps (ΔEH-L) to locate the most potential therapeutic candidates. The PASS prediction (Pa > Pi score) showed that proposed metal complexes have kinase inhibitors, antioxidative, and antischistosomal activities with potential molecular docking scores (> -7 kcal/mol) against selected targeted enzymes. Further, the MD-simulation (RMSD, RMSF, Rg, and H-bonds) of the most potential docking complex, 'HER2-6d', showed a minimum deviation similar to the standard drug (lapatinib) at 100 ns, indicating that 6d could be a potential noncovalent anticancer inhibitor. In addition, metal complexes possess a non-toxic and ideal drug-ability profiles, and positive electron space in an excited state increases the binding affinity towards target enzymes. Among all six ligands, 6c and 6d were the two most multipotent therapeutic agents from the above analyses. In summary, this could be a feasible approach towards the utilization of phytochemicals in mainstream therapeutic applications, where bioinformatics tools help to select a lead drug candidate at an early stage and guide for higher experimental success by proceeding with potential candidates.Communicated by Ramaswamy H. Sarma.

In vitro and in silico assessment of anti-biofilm and anti-quorum sensing properties of 2,4-Di-tert butylphenol against Acinetobacter baumannii.

Introduction. Acinetobacter baumannii is a nosocomial pathogen with a high potential to cause food-borne infections. It is designated as a critical pathogen by the World Health Organization due to its multi-drug resistance and mortalities reported. Biofilm governs major virulence factors, which promotes drug resistance in A. baumannii. Thus, a compound with minimum selection pressure on the pathogen can be helpful to breach biofilm-related virulence.Hypothesis/Gap Statement. To identify anti-biofilm and anti-virulent metabolites from extracts of wild Mangifera indica (mango) brine pickle bacteria that diminishes pathogenesis and resistance of A. baumannii.Aim. This study reports anti-biofilm and anti-quorum sensing (QS) efficacy of secondary metabolites from bacterial isolates of fermented food origin.Method. Cell-free supernatants (CFS) of 13 bacterial isolates from fermented mango brine pickles were screened for their efficiency in inhibiting biofilm formation and GC-MS was used to identify its metabolites. Anti-biofilm metabolite was tested on early and mature biofilms, pellicle formation, extra polymeric substances (EPS), cellular adherence, motility and resistance of A. baumannii. Gene expression and in silico studies were also carried out to validate the compounds efficacy.Results. CFS of TMP6b identified as Bacillus vallismortis, inhibited biofilm production (83.02 %). Of these, major compound was identified as 2,4-Di-tert-butyl phenol (2,4-DBP). At sub-lethal concentrations, 2,4-DBP disrupted both early and mature biofilm formation. Treatment with 2,4-DBP destructed in situ biofilm formed on glass and plastic. In addition, key virulence traits like pellicle (77.5 %), surfactant (95.3 %), EPS production (3-fold) and cell adherence (65.55 %) reduced significantly. A. baumannii cells treated with 2,4-DBP showed enhanced sensitivity towards antibiotics, oxide radicals and blood cells. Expression of biofilm-concomitant virulence genes like csuA/B, pgaC, pgaA, bap, bfmR, katE and ompA along with QS genes abaI, abaR significantly decreased. The in silico studies further validated the higher binding affinity of 2,4-DBP to the AbaR protein than the cognate ligand molecule.Conclusion. To our knowledge, this is the first report to demonstrate 2,4- DBP has anti-pathogenic potential alone and with antibiotics by in vitro, and in silico studies against A. baumannii. It also indicates its potential use in therapeutics and bio-preservatives.

pH modulates the role of SP6 RNA polymerase in transcription process: an in silico study.

SP6 RNA polymerase (SP6 RNAP) is an essential enzyme for the transcription process in SP6 bacteriophage. SP6 RNAP plays a vital role in mRNA vaccine designing technology and other translational biotechnology research due to the high specificity towards its promoter. The self-replicating performance also put this polymerase to study extensively. Despite of the reports emphasizing the function of this enzyme, a detailed structural and functional understanding of RNA polymerase is not reported so far. Here, we report the first-ever information about SP6RNAP structure and its effect on promoter binding at different pH environments using molecular docking and molecular dynamics simulation (MDS) study. We also report the changes in polymerase conformations in different pH conditions using in-silico approach. The docking study was also performed for SP6 RNAP with SP6 promoter at different pH environments using the in-silico docking tools and conducted the MDS study for complexes. MM/PBSA and per residue energy contribution has been performed at three different pH environments. The structural aspects confirmed that the pH 7.9 state favors the polymerase functional activity in the transcription process which was in the range reported using transcription assay. This polymerase's unique features may play its emerging role as an efficient transcription factor in translational biological research.Communicated by Ramaswamy H. Sarma.

Computational analysis of marine algal compounds for obesity management against pancreatic lipase.

Obesity is considered a global crisis because of its increased risk factors triggered by lifestyle changes. The prevalence of this condition is increasing at an alarming rate, giving rise to development of novel drugs. Pancreatic lipase possesses higher efficacy in inhibiting this condition among the other drug targets. In this study, virtual screening of 126 plant-derived anti-obesity compounds and 1110 marine algal compounds from seaweed metabolite database were screened and targeted against pancreatic lipase and ranked based on their binding affinity values. A total of 530 compounds that possessed best docked scores of less than -6 kcal/mol were checked for Lipinski's properties through Swiss ADME. Furthermore, these compounds were subjected to toxicity prediction using PROTOX II server. As much as 38 compounds were found to be non-toxic and were subjected to molecular docking analysis. Based on the binding energy, the following compounds RG012 (-10.15 kcal/mol), LIG42 (-9.7 kcal/mol), BC010 (-8.47 kcal/mol), RL073 (-8.2 kcal/mol), and LIG46 (-8.03 kcal/mol) were selected exhibiting higher binding affinity when compared to the standard drug (Orlistat) and hence these compounds were subjected to molecular dynamics simulation using GROMACS. BC010 complex revealed a stable interaction within the binding pocket and the binding free energy is -158.208 kJ/mol which is higher when compared to other complexes in 100 ns simulation. BC010 ((7S,11S,12S,14R)-4',14-dimethoxyamentol) from brown algae Cystophora fibrosa could be considered as a potential drug candidate to suppress obesity by inhibiting pancreatic lipase.Communicated by Ramaswamy H. Sarma.